The term “ethylene-propylene-diene interpolymer,” (or “EPDM”) as used herein, is a saturated interpolymer chain composed of units derived from ethylene, propylene, and a diene. EPDM has a wide range of applications, such as insulation for wire and cable, for example. Power utility companies continue to demand power cable with longer service life (40+ years). The dielectric properties of the cable insulation contribute to the service life of power cable. It is known that polymerization residuals and/or impurities can negatively affect the dielectric properties of EPDM, and correspondingly adversely impact the service life of power cable.
The art therefore recognizes the need for EPDM with improved dielectric properties. The art further recognizes the need for reducing polymerization residuals in EPDM while simultaneously maintaining the processability of the EPDM for power cable production.